NetNews Usenet Archive 1992 #19/NN_1992_19.iso/spool/comp/lang/verilog/331

Text File | 1992-09-01 | 2.1 KB | 69 lines

Newsgroups: comp.lang.verilog
Path: sparky!uunet!Cadence.COM!acae037!eversole
From: [e-mail] (Richard Eversole; x6239)
Subject: Re: readmem
Message-ID: <[e-mail]>
Sender: [e-mail] (Usenet News)
Nntp-Posting-Host: acae037
Reply-To: [e-mail] (Richard Eversole; x6239)
Organization: Cadence Design Systems, Inc.
References: <[e-mail]> <[e-mail]>
Date: Mon, 31 Aug 1992 13:35:12 GMT
Lines: 55

In article <[e-mail]>, [e-mail] (Eric Williams) writes:
|> In <[e-mail]> [e-mail] (Justin Strohschneider) writes:
|>
|> >For the simulation of a computer architecture it is necessary for me to
|> >define a RAM as a module and to have several incarnations of this RAM with
|> >different contents.
|> >The $readmem system task can be used to fill a memory array with data.
|> >The problem I have is to realize different filenames in the $readmem task.
|> >I would be very glad if anybody could give me some information concerning
|> >this problem.
|>
|> Two ways you could do this.  The first method simply does the readmemh from
|> the module that instantiates the memories.  It sounds like you're trying to
|> put the readmem in the module that contains the memory.  In this case try
|> method 2 which passes this filename into the module as an input.
|>
|> -Eric Williams


Another alternative (and prefered over second option shown by Eric is
to use the parameter construct. There are two ways to use this:
override with defparam and module parameter value assignment.
Both are shown in the following simple example. Note I only use
a $display but it could be $readmemh or whatever.


module test;

wire A;

memmod #("FILEA") U1(A); // Parameter Value Assignment

defparam U2.FOO = "BAR";
memmod U2(A);

endmodule

module memmod(A);
input A;

parameter FOO = "";

initial
 $display("%s",FOO);
endmodule


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